Last week, Indiana football coach Kevin Wilson abruptly resigned amid a second investigation into whether he mistreated players. Athletic Director Fred Glass hoped to pacify the public in a news conference by citing ever-popular “philosophical differences” and insisted there was “no smoking gun.”

In the days that followed, of course, the proverbial smoking gun emerged. It was locked, loaded and pointed at the heads of injured players who had the audacity to get injured. The nerve of college kids these days. Who would have imagined football players getting hurt while playing football?

Wilson’s response, according to several reports, was to belittle them for not getting back on the field. He doubted their toughness and questioned their manhood. He made them feel worthless. He intimidated members of the training staff who reportedly were reluctant to report injuries because they feared his wrath.

“He would come over and yell at us, saying, ‘I’m paying $70,000 a year for you to sit on your ...,’ ” former defensive lineman Nick Carovillano told the IndyStar. “That happened about halfway through the season and carried on to the end of it. If you were injured, he just wanted to make you feel like crap. He just wanted to make you feel bad, so you basically would stop being injured.”

Carovillano told the newspaper that he was instructed to lift weights after suffering a back injury. His own doctor later found three damaged discs and a bone fragment in his back, according to the newspaper, and Carovillano left the program last year. As it turned out, he was hardly alone. Others made similar comments about Wilson.

Former running back Laray Smith said he felt Wilson no longer cared about him after he suffered a back injury. Another player told the student newspaper that he was diagnosed with a sprained finger when actually he had a serious knuckle injury that led to wrist surgery. Another spoke of being put through a strenuous workout after suffering a concussion and ending up with concussion-related symptoms for months.

Other former players disputed such claims and supported the coach. Some claimed Wilson was actually overprotective when it came to injuries. Some embraced his hard-driving style and extolled his methods of instilling discipline and toughness, praising him for preparing them in life and maximizing their ability on the field.

We can assume no grand conspiracy was concocted by former injured players, but we can also trust that others weren’t lying about an embattled coach who already had been shown the door. The truth, as usual, depended on perception.

In many cases, there is no clear definition of suitable behavior. The same coaches can be praised for motivating players or condemned for abusing them. The gray area changes from coach to coach and player to player, from one generation to the next. One man’s intensity is another man’s crazy.

The NCAA doesn’t have specific regulations that outline how players should be treated, either. Schools determine how individual coaching styles suit their programs, contributing to a line that has become blurred. Attitudes among young athletes changed faster than many coaches changed with the times.

What’s accepted? It’s easier to understand what’s not.

Coaches shouldn’t grab players by the neck, as Bobby Knight did at Indiana, or kick them and hurl basketballs and gay slurs at them, as Mike Rice did at Rutgers, or force them to swim until they blacked out, as Greg Winslow did at Utah, or punch an opposing player, as Woody Hayes did at Ohio State. Many other coaches have cursed athletes to tears behind closed doors.

Let me be clear: A vast majority of coaches, in all sports and on all levels, run reputable programs. Their players graduate. They build strong relationships. They contribute to making their players better people. They’re well-intentioned people who don’t need How-To instructions from the NCAA.

But college sports, especially at the Division I level, can be a minefield. The minute an athlete accepts a dollar from a university is the minute the coach owns their time and energy. In many ways, sports become full-time jobs. Athletes are treated like employees and compensated with scholarships.

Not helping the cause are egomaniacal coaches who believe they created their own kingdom. The more money teams generate for their universities, the more likely they will be given big contracts for big money, the more they become empowered. Abuse of that power creates a culture that can become hazardous to their players’ health.

Certain coaches preach about teams becoming families even though they would never treat their own children with the little regard they show their players. Too many talk about leadership and show little. Parents pass the baton and hope for the best. In an effort to satisfy everyone, athletes follow orders.

Wilson’s implication that he paid $70,000 a year for anyone, while utterly ludicrous, came with an underlying suggestion that everyone on his roster was indebted to him. He didn’t pay a penny for scholarships. If he did, Indiana would have faced NCAA sanctions from now until eternity.

Never mind that Indiana’s price tag for full tuition, room and board and other expenses for out-of-state residents is about $48,000, not $70,000. That would have diminished his point. He could have funded 52 scholarships based on his $2.55 million salary in 2016, the first of a six-year contract extension worth $15.3 million.

Indiana nearly doubled his money after he led the Hoosiers to the Pinstripe Bowl last season, their first bowl since 2008. He had a 26-47 record over six seasons and didn’t finish above .500 in any of them. The Hoosiers were bowl eligible with a 6-6 record last year. Apparently, marginal success warranted a massive pay raise.

Wilson’s players signed up to be coached, not ridiculed. He overestimated his importance when he demeaned injured players for his own benefit or jollies. He abused his authority, crossed the blurry line and became dangerous when he inexcusably started firing verbal shots at defenseless players.

Thankfully, he handed over the smoking gun.

Bucky Gleason– Bucky Gleason is senior sports columnist for The Buffalo News. He has covered sports on all levels since 1992. He is a terrible golfer who remains undefeated in match play on the 19th hole. He lives in Hamburg with his wife and four children.